Intravascular device for venting an inflatable chamber

ABSTRACT

An intravascular device for venting an inflatable chamber and methods for using the device are disclosed. The intravascular device generally includes three components, namely a catheter or cannula, an inflatable member, and a selective degassing element. The inflatable member is typically a balloon. The catheter or cannula is typically hollow with a first lumen extending between an inflation port and the interior of the inflatable member and a second lumen extending between the interior of the inflatable member and an exhaust port. The selective degassing element is typically positioned between the inflatable member and the exhaust port and occupies the entire cross-sectional area of the second lumen. When in a closed position, the selective element prevents the passage of liquid from the interior of the inflatable member, through the exhaust port. When in an open position, the selective element permits gas entrained within the inflatable member to be expelled from the device, via the exhaust port.

FIELD OF THE INVENTION

[0001] The present invention relates generally to intravascular devicesthat incorporate an inflatable member, and more particularly to devicesof this type which enable rapid and efficient degassing of the device.The present invention also relates to methods for rapidly andefficiently degassing an intravascular device that incorporates aninflatable member.

BACKGROUND OF THE INVENTION

[0002] During the course of many medical procedures, it is oftennecessary to introduce a catheter or cannula that incorporates aninflatable member, such as a balloon catheter, into the circulatorysystem of the patient. However, before such a device can be safelyutilized, the physician, or other qualified medical personnel, mustinstitute a degassing process. That is, gasses, such as air, entrainedin the device during manufacturing and packaging must be displaced sothat if the inflatable member should leak or rupture during use, thechance of gas being released into the circulatory system is minimized.

[0003] For example, when utilizing PTCA catheters or intra-aorticballoon occlusion catheters/cannula, medical personnel must typicallyperform repeated liquid inflation and deflation cycles prior toplacement of the device, in an effort to remove all entrapped air fromthe inflatable member. This tedious process is often difficult toaccomplish. Furthermore, the degassing process is time consuming,inconvenient, and costly.

[0004] The need to perform numerous inflation and deflation cycles in aneffort to remove all entrained gasses can also severely limit the designof the overall device. In particular, intravascular devices that have alarge volume of inflation tubing in comparison to the overall volume ofthe inflatable member tend to be especially difficult to degas.

[0005] Accordingly, there is a need for an intravascular device thatincorporates an inflatable member, such as a balloon catheter, whichpermits rapid and efficient degassing of the device. Furthermore, thereis a need for such a device which also places few, if any, restrictionson design choices. The present invention satisfies both of these needs.

SUMMARY OF THE INVENTION

[0006] The present invention relates to medical devices and theirmethods of use, particularly intravascular catheters and cannula whichincorporate an inflatable member. The intravascular device of thepresent invention generally includes three components, namely: (1) acatheter or cannula; (2) an inflatable member; and (3) a selectivedegassing element.

[0007] The inflatable member is typically a balloon having a definedinterior. The balloon is capable of expansion to a defined volume whenthe interior of the balloon is infused with liquid.

[0008] The catheter or cannula is typically hollow. The proximal end ofthe catheter or cannula incorporates an inflation port. The distal endof the catheter or cannula incorporates an exhaust port. A first lumenextends within the catheter or cannula from the inflation port to theinterior of the inflatable member. A second lumen extends within thecatheter or cannula from the exhaust port to the interior of theinflatable member. The first lumen enables liquid, infused into thecatheter or cannula through the inflation port, to flow into theinterior of the inflatable member. The second lumen enables gas,entrained within the interior of the inflatable member, to be expelledfrom the catheter or cannula through the exhaust port.

[0009] The selective degassing element typically occupies the entirecross-sectional area of the second lumen and is preferably positionedacross the second lumen near the exhaust port. When in a closedposition, the selective element prevents the passage of liquid from theinterior of the inflatable member, through the exhaust port, via thesecond lumen. However, when the selective element is in an openposition, the gas entrained within the inflatable member is permitted topass through the second lumen to the exhaust port. This flow of gas maybe expedited, in some instances, by the infusion of liquid into thedevice through the inflation port—causing any gas entrained within thefirst lumen, the second lumen, or the interior of the inflatable memberto migrate toward the selective degassing element, pass through theselective degassing element, and be expelled from the catheter orcannula through the exhaust port.

[0010] The selective degassing element can take a number of forms andcan be placed in an open or closed position in a number of ways. Incertain embodiments, the selective degassing element is anon-mechanically actuated valve, a plug, a membrane, a mechanicallyactuated valve, or a hydrophobic filter. The non-mechanically actuatedvalve, the plug, and the membrane are typically in a closed positionunless placed in an open position by insertion of a needle or hollowtube. The hydrophobic filter is always in an open position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a cross-sectional view of one preferred embodiment ofthe present invention.

[0012]FIG. 2 is another cross-sectional view of one preferred embodimentof the present invention illustrating the non-mechanically actuatedvalve in a closed configuration.

[0013]FIG. 3 is a cross-sectional view of one preferred embodiment ofthe present invention illustrating the non-mechanically actuated valvein an open configuration.

[0014]FIG. 4 is a cross-sectional view of a second preferred embodimentof the present invention illustrating the plug in a closedconfiguration.

[0015]FIG. 5 is a cross-sectional view of a second preferred embodimentof the present invention illustrating the plug in an open configuration.

[0016]FIG. 6 is a cross-sectional view of a third preferred embodimentof the present invention illustrating the membrane in a closedconfiguration.

[0017]FIG. 7 is a cross-sectional view of a third preferred embodimentof the present invention illustrating the membrane in an openconfiguration.

[0018]FIG. 8 is a cross-sectional view of a fourth preferred embodimentof the present invention illustrating the mechanically actuated valve ina closed configuration.

[0019]FIG. 9 is a cross-sectional view of a fourth preferred embodimentof the present invention illustrating the mechanically actuated valve inan open configuration.

[0020]FIG. 10 is a cross-sectional view of a fifth preferred embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Turning now to the drawings, FIGS. 1-10 show various preferredembodiments of the present invention. As shown in FIG. 1, theintravascular device 2 of the present invention generally includes threecomponents, namely an inflatable member 4, a catheter or cannula 6, anda selective degassing element 8.

[0022] The inflatable member 4 is typically a balloon having a definedinterior 10 and exterior 12. The inflatable member 4 is capable ofexpansion to a defined volume when the interior 10 of the inflatablemember 4 is infused with liquid.

[0023] The catheter or cannula 6 is typically hollow and has a proximal14 and a distal 16 end. The proximal end 14 incorporates an inflationport 18. A first lumen 20 extends within the catheter or cannulae 6 fromthe inflation port 18 to the interior 10 of the inflatable member 4.This first lumen 20 enables liquid, infused into the catheter or cannula6 through the inflation port 18, to flow into the interior 10 of theinflatable member 4. The distal end 16 incorporates an exhaust port 22.A second lumen 24 extends within the catheter or cannula 6 from theexhaust port 22 to the interior 10 of the inflatable member 4. Thissecond lumen 24 enables gas, entrained within the interior 10 of theinflatable member 4, to be expelled from the catheter or cannula 6through the exhaust port 22.

[0024] The selective degassing element 8 typically occupies the entirecross sectional area of the second lumen 24. Preferably, the selectiveelement 8 is positioned across the second lumen 24 near the exhaust port22. When liquid is infused through the inflation port 18, any gasentrained within the first lumen 20, the interior 10 of the inflatablemember 4, or the second lumen 24 (between the interior 10 of theinflatable member 4 and the selective degassing element 8), is allowedto pass through the exhaust port 22 when the selective element 8 is inthe open position.

[0025] As shown in FIG. 2, the selective element of the first preferredembodiment of the present invention is a non-mechanically actuated valve26. Such a non-mechanically actuated valve 26 can be manufactured from avariety of materials which should be obvious to those of ordinary skillin the art. Preferably, the non-mechanically actuated valve 26 of thefirst preferred embodiment of the present invention is manufactured fromslited rubber or a self-sealing elastomer. The non-mechanically actuatedvalve 26 is typically maintained in a closed position—preventing thepassage of liquid from the interior 10 of the inflatable member 4,through the exhaust port 22.

[0026] However, as shown in FIG. 3, when a needle or hollow tube 28 isinserted into the non-mechanically actuated valve 26, thenon-mechanically actuated valve 26 is placed in an open position and apassage is formed for the escape of gas from the first lumen 20, thesecond lumen 24, and the interior 10 of the inflatable member 4 throughthe exhaust port 22. This escape of gas may be aided by flushing thefirst lumen 20, the second lumen 24, and the interior 10 of theinflatable member 4 with large volumes of liquid through the inflationport 18, with the liquid flow helping direct the entrapped gassesthrough the non-mechanically actuated valve 26 and the exhaust port 22.When the needle or hollow tube 28 is withdrawn from the non-mechanicallyactuated valve 26, the non-mechanically actuated valve 26 is returned toa closed position.

[0027] As shown in FIG. 4, the selective degassing element of the secondpreferred embodiment of the present invention is a plug 30. Such a plug30 can be manufactured from a variety of materials which should beobvious to those of ordinary skill in the art. Preferably, the plug 30of the second preferred embodiment of the present invention ismanufactured from latex, silicone rubber or other “self-heating”material. The plug 30 is typically maintained in a closedposition—preventing the passage of liquid from the interior 10 of theinflatable member 4, through the exhaust port 22.

[0028] However, as shown in FIG. 5, when a needle or hollow tube 28 isinserted through the plug 30, the plug 30 is placed in an open positionand a passage is formed for the escape of gas from the first lumen 20,the second lumen 24, and the interior 10 of the inflatable member 4through the exhaust port 22. This escape of gas may be aided by flushingthe first lumen 20, the second lumen 24, and the interior 10 of theinflatable member 4 with large volumes of liquid through the inflationport 18, with the liquid flow helping direct the entrapped gassesthrough the plug 30 and the exhaust port 22. When the needle or hollowtube 28 is withdrawn from the plug 30, the plug 30 is returned to aclosed position.

[0029] As shown in FIG. 6, the selective degassing element of the thirdpreferred embodiment of the present invention is a membrane 32. Such amembrane 32 can be manufactured from a variety of materials which shouldbe obvious to those of ordinary skill in the aft. Preferably, themembrane 32 of the third preferred embodiment of the present inventionis manufactured from Gortex or nylon mesh. The membrane 32 is typicallymaintained in a closed position—preventing the passage of liquid fromthe interior 10 of the inflatable member 4, through the exhaust port 22.

[0030] However, as shown in FIG. 7, when a needle or hollow tube 28 isinserted through the membrane 32, the membrane 32 is placed in an openposition and a passage is formed for the escape of gas from the firstlumen 20, the second lumen 24, and the interior 10 of the inflatablemember 4 through the exhaust port 22. This escape of gas may be aided byflushing the first lumen 20, the second lumen 24, and the interior 10 ofthe inflatable member 4 with large volumes of liquid through theinflation port 18, with the liquid flow helping direct the entrappedgasses through the membrane 32 and the exhaust port 22. When the needleor hollow tube 28 is withdrawn from the membrane 32, the membrane 32 isreturned to a closed position.

[0031] As shown in FIG. 8, the selective degassing element of the fourthpreferred embodiment of the present invention is a mechanically actuatedvalve 34. Such a mechanically actuated valve 34 can be selected from avariety of valves which should be obvious to those of ordinary skill inthe art. Preferably, the mechanically actuated valve 34 of the fourthpreferred embodiment of the present invention is a one-way check valve.The mechanically actuated valve 34 is typically maintained in a closedposition preventing the passage of liquid from the interior 10 of theinflatable member 4, through the exhaust port 22.

[0032] However, as shown in FIG. 9, when the mechanically actuated valve34 is placed in an open position, a passage is formed for the escape ofgas from the first lumen 20, the second lumen 24, and the interior 10 ofthe inflatable member 4 through the exhaust port 22. This escape of gasmay be aided by flushing the first lumen 20, the second lumen 24, andthe interior 10 of the inflatable member 4 with large volumes of liquidthrough the inflation port 18, with the liquid flow helping direct theentrapped gasses through the mechanically actuated valve 34 and theexhaust port 22. When the mechanically actuated valve 34 is returned toa closed position, the flow of liquid or gas through the exhaust port 22will cease.

[0033] As shown in FIG. 10, the selective degassing element of the fifthpreferred embodiment of the present invention is a hydrophobic filter36. Such a hydrophobic filter 36 is preferably a gas permeable, liquidimpermeable, membrane or plug material. When liquid is infused throughthe inflation port 18, any gas entrained in the first lumen 20, thesecond lumen 24, or the interior 10 of the inflatable member 4 migratestoward the hydrophobic filter 36. The gas then selectively passesthrough the hydrophobic filter 36 and the exhaust port 22. Thehydrophobic filter 36 is always in an open position.

[0034] While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the appended claims.

What is claimed is:
 1. An intravascular device, comprising: an elongatemember having a proximal end, a distal end, and a distal region; aballoon having an interior chamber and being mounted on the distalregion of the elongate member; an inflation tube having an inflationlumen communicating with the interior of said balloon and an inflationport, said inflation lumen for infusing a liquid into the balloon; aventing tube having a venting lumen communicating with the interior ofsaid balloon and an exhaust port, said venting lumen for expulsion ofgas from the interior of said balloon through said exhaust port; aselective degassing element, positioned across said venting lumen forthe expulsion of gas from the balloon through said exhaust port and forpreventing the expulsion of liquid from the balloon through said exhaustport.
 2. The intravascular device of claim 1, wherein said elongatemember is a catheter.
 3. The intravascular device of claim 1, whereinsaid elongate member is a cannula.
 4. The intravascular device of claim2, wherein said selective degassing element is a non-mechanicallyactuated valve.
 5. The intravascular device of claim 4, wherein saidvalve is manufactured from slited rubber.
 6. The intravascular device ofclaim 4, wherein said valve is manufactured from a self sealingelastomer.
 7. The intravascular device of claim 2, wherein saidselective degassing element is a plug.
 8. The intravascular device ofclaim 7, wherein said plug is manufactured from sintered polyetheyene.9. The intravascular device of claim 2, wherein said selective degassingelement is a membrane.
 10. The intravascular device of claim 9, whereinsaid membrane is manufactured from Gortex.
 11. The intravascular deviceof claim 9, wherein said membrane is manufactured from nylon mesh. 12.The intravascular device of claim 2, wherein said selective degassingelement is a mechanically actuated valve.
 13. The intravascular deviceof claim 12, wherein said valve is a one-way check valve.
 14. Theintravascular device of claim 2, wherein said selective degassingelement is a hydrophobic filter.
 15. The intravascular device of claim14, wherein said filter is a gas permeable membrane.
 16. Theintravascular device of claim 2, wherein said selective degassingelement allows the expulsion of gas and liquid from the interior of saidballoon through said exhaust port when said selective degassing elementis in an open position, and prevents the expulsion of gas and liquidfrom the interior of said balloon through said exhaust port when saidselective degassing element is in a closed position.
 17. Theintravascular device of claim 2, wherein said selective degassingelement is capable of simultaneously allowing the expulsion of gas fromthe interior of said balloon through said exhaust port while preventingthe expulsion of liquid from the interior of said balloon through saidexhaust port.
 18. An intravascular device, comprising: an inflatablemember having an interior and an exterior; a first lumen connecting theinterior of said inflatable member and the exterior of said inflatablemember, said first lumen capable of allowing the infusion of liquid fromthe exterior of said inflatable member into the interior of saidinflatable member; a second lumen connecting the interior of saidinflatable member and the exterior of said inflatable member, saidsecond lumen capable of allowing the expulsion of gas from the interiorof said inflatable member to the exterior of said inflatable member; aselective degassing element, said element positioned across said secondlumen and capable of allowing the expulsion of gas from the interior ofsaid inflatable member to the exterior of said inflatable member throughsaid second lumen and capable of preventing the expulsion of liquid fromthe interior of said inflatable member to the exterior of saidinflatable member through said second lumen.
 19. An intravasculardevice, comprising: a catheter or cannulae; a balloon attached to saidcatheter or cannulae, said balloon having an interior and an exterior; afirst lumen within said catheter or cannulae, said first lumenconnecting the interior of said balloon and an inflation port andcapable of allowing the infusion of liquid through said inflation portinto the interior of said balloon; a second lumen within said catheteror cannulae, said second lumen connecting the interior of said balloonand an exhaust port and capable of allowing the expulsion of gas fromthe interior of said balloon through said exhaust port; a selectivedegassing element, said element positioned across said second lumen andcapable of allowing the expulsion of gas from the interior of saidballoon through said exhaust port and capable of preventing theexpulsion of liquid from the interior of said balloon through saidexhaust port.
 20. A method for degassing an intravascular device,comprising the steps of: providing an elongate member having a proximalregion and a distal region, a balloon mounted on the distal region, aninflation tube communicating with the interior of said balloon and aninflation port, a venting tube communicating with the interior of saidballoon and an exhaust port, and a selective degassing element, saidelement positioned within said venting lumen for expulsion of gas fromsaid balloon through said exhaust port and for preventing the expulsionof liquid from said balloon through said exhaust port; opening saiddegassing element; and injecting liquid into said balloon, wherein gasis purged from the balloon through said venting lumen, through saiddegassing element, and through said exhaust port.
 21. The method ofclaim 20, wherein said selective degassing element is placed in an openposition by inserting a needle or hollow tube into said element.
 22. Themethod of claim 20, wherein said selective degassing element is placedin an open position by inserting a needle or hollow tube through saidelement.
 23. The method of claim 20, wherein the elongate member in acannula.
 24. The method of claim 20, wherein the elongate member is acatheter.
 25. The method of claim 20, wherein the selective degassingelement is a non-mechanical valve.
 26. The method of claim 20, whereinthe selective degassing element is a mechanical valve.
 27. The method ofclaim 25, wherein the valve is selected from the group consisting ofslited rubber, self sealing elastomer, a plug, a membrane, and ahydrophobic filter.